In a radio frequency (RF) communication system suitable for transmitting voice messages to portable or other receivers, such as selective call receivers (e.g., pagers), single sideband modulation techniques are employed for reasons of spectrum efficiency. Presently, only one of the upper or lower sidebands is used for carrying information to the receiver. Demodulating and reconstructing a message that is sent entirely on the upper or lower sideband requires that the receiver sample both the in-phase (I) component and the quadrature (Q) component of the signal for the duration of the message on the channel. Both sidebands are recovered, but the message is contained in only one of the sidebands. The information in the other sideband is discarded.
That only one of the sidebands actually carries the message is inefficient use of "air" time resulting in "traffic" inefficiencies on the assigned RF band. Furthermore, this is inefficient use of the receiver processing power and needlessly consumes battery energy in a portable receiver device .